Coaster



FIG. 1 is a top plan view of a coaster showing my new design;

FIG. 2 is a side elevational view thereof;

FIG. 3 is a bottom plan view thereof; and,

FIG. 4 is a top plan view of a coaster in accordance with my design showing an optical effect produced by the surface characteristics of the top surface thereof.

This design is characterized by the upper surface of the coaster having the appearance of the soundtrack msurface of a compact disk record, which surface produces, in an otherwise plain neutral surface, multi-colored optical effects that characterize a visual aspect of this design. 

The ornamental design for a coaster, as shown and described. 